dispatcher

--this file is an API for dynamically adding coroutines to the running set
local dbg = true
local routines = {}

function setDebug(b) if type(b) ~= "boolean" then error("Expected boolean",2) end dbg = b return end

function add(f,...) --add coro that starts at f(...)
  if (type(f) ~= "function") then error("Expected function",2) return  end
  local coro = coroutine.create(f)
  routines[coro] = {func=f,args={...},started=false,filter=nil,persistent=false}
  return
end

function addPersistent(f,...) --as add, but dispatcher revives coro when it dies
  if (type(f) ~= "function") then error("Expected function",2) return  end
  local coro = coroutine.create(f)
  routines[coro] = {func=f,args={...},started=false,filter=nil,persistent=true,}
  return
end

function begin(f,...) --main body of dispatcher
  if (f ~= nil) then
    if (type(f) ~= "function") then error("Expected function",2) return  end
    add(f,...)
  end

  local event = {}
  while true do
    local mfd = {}
    for coro,t in pairs(routines) do
      if (coro ~= nil) then
        if (t.started == false) then
          t.started = true
          local _,param = coroutine.resume(coro,unpack(t.args))
          t.filter = param
          if (dbg) then print("thread returned: ",coro) for _,v in pairs({param}) do write("  ") print(v) end end
        else
          if ((t.filter == nil) or (t.filter == event[1]) or (event[1] == "terminate")) then
             if (dbg) then print("resuming thread: ",coro) end
             local _,param = coroutine.resume(coro,unpack(event))
             t.filter = param
             if (dbg) then print("thread returned: ",coro) for _,v in pairs({param}) do write("  ") print(v) end end
          end
        end
        if (coroutine.status(coro) == "dead") then
          if (dbg) then print("thread died: ",coro) end
          if (t.persistent == true) then --revive persistent coroutine with same args
            if (dbg) then print("reviving persistent thread:") write("  ") print("coro") write("  ") print(t.func) for _,v in pairs(t.args) do write("  ") print(v) end end
            addPersistent(t.func,unpack(t.args))
          end
          table.insert(mfd,coro)
        end
      end
    end
    for _,coro in pairs(mfd) do routines[coro] = nil end
    event = {os.pullEvent()}
  end
end